Don't fiddle with NDEBUG in C code (GH-16511)

* Don't fiddle with NDEBUG in C code

It is way to late to do this in php.h, since assert.h has already been
included.  Even pushing that down to zend_portability.h may not have
the desired effect.  Instead we define or undefine NDEBUG as CFLAG, so
that it works in all circumstances.

As a last resort we fail at build time, if `NDEBUG` is defined when
`ZEND_DEBUG` is enabled.

We also remove the useless workaround in zend_test to include assert.h
again, since that usually won't have any effect anyway.

Co-authored-by: Arnaud Le Blanc <arnaud.lb@gmail.com>

Zend/zend_portability.h

@@ -47,6 +47,9 @@
 #include "../TSRM/TSRM.h"
 
 #include <stdio.h>
+#if ZEND_DEBUG && defined(NDEBUG)
+# error "NDEBUG must not be defined when ZEND_DEBUG is enabled"
+#endif
 #include <assert.h>
 #include <math.h>
 

configure.ac

@@ -799,6 +799,8 @@ PHP_ARG_ENABLE([debug],
 AS_VAR_IF([PHP_DEBUG], [yes], [
   PHP_DEBUG=1
   ZEND_DEBUG=yes
+  CFLAGS="$CFLAGS -UNDEBUG"
+  CXXFLAGS="$CXXFLAGS -UNDEBUG"
   PHP_REMOVE_OPTIMIZATION_FLAGS
   dnl Add -O0 only if GCC or ICC is used.
   if test "$GCC" = "yes" || test "$ICC" = "yes"; then
@@ -817,6 +819,8 @@ AS_VAR_IF([PHP_DEBUG], [yes], [
 ], [
   PHP_DEBUG=0
   ZEND_DEBUG=no
+  CFLAGS="$CFLAGS -DNDEBUG"
+  CXXFLAGS="$CXXFLAGS -DNDEBUG"
 ])
 
 PHP_ARG_ENABLE([debug-assertions],
@@ -829,6 +833,8 @@ PHP_ARG_ENABLE([debug-assertions],
 AS_VAR_IF([PHP_DEBUG_ASSERTIONS], [yes], [
   PHP_DEBUG=1
   ZEND_DEBUG=yes
+  CFLAGS="$CFLAGS -UNDEBUG"
+  CXXFLAGS="$CXXFLAGS -UNDEBUG"
 ])
 
 AC_ARG_ENABLE([zts],

ext/zend_test/test.c

@@ -38,12 +38,6 @@
 #include "zend_exceptions.h"
 #include "zend_mm_custom_handlers.h"
 
-// `php.h` sets `NDEBUG` when not `PHP_DEBUG` which will make `assert()` from
-// assert.h a no-op. In order to have `assert()` working on NDEBUG builds, we
-// undefine `NDEBUG` and re-include assert.h
-#undef NDEBUG
-#include "assert.h"
-
 #if defined(HAVE_LIBXML) && !defined(PHP_WIN32)
 # include <libxml/globals.h>
 # include <libxml/parser.h>

main/php.h

@@ -109,13 +109,6 @@ typedef int pid_t;
 # endif
 #endif
 
-#if PHP_DEBUG
-#undef NDEBUG
-#else
-#ifndef NDEBUG
-#define NDEBUG
-#endif
-#endif
 #include <assert.h>
 
 #ifdef HAVE_UNIX_H

win32/build/confutils.js

@@ -3429,7 +3429,7 @@ function toolset_setup_common_libs()
 function toolset_setup_build_mode()
 {
 	if (PHP_DEBUG == "yes") {
-		ADD_FLAG("CFLAGS", "/LDd /MDd /Od /D ZEND_DEBUG=1 " +
+		ADD_FLAG("CFLAGS", "/LDd /MDd /Od /U NDebug /U NDEBUG /D ZEND_DEBUG=1 " +
 			(TARGET_ARCH == 'x86'?"/ZI":"/Zi"));
 		ADD_FLAG("LDFLAGS", "/debug");
 		// Avoid problems when linking to release libraries that use the release